Sunday Science: Make your own bouncy ball 週日科學: 自製彈跳球

Welcome to Sunday Science! Every Sunday during the summer, we're going to guide you through some cool experiments that you can do at home. It's a good idea for you to keep a record of what you do in a Science Journal. That way you can record what you learn, compare results and maybe use them to design new experiments! Have a look at the Science Journal box for some ideas to get you started. Remember always ask a grown-up's permission before trying out an experiment.
歡迎閱讀《週日科學版》！在暑假期間，我們每週日都要為你介紹可以在家中進行的有趣科學實驗。你可以在《科學日誌》中記錄自己做了哪些活動，這樣就可以將所學的紀錄下來，比較這些結果，也許還可以利用它們來設計新的實驗！先看一下《科學日誌》的點子再開始吧。展開實驗之前，記得要獲得大人許可喔！

PHOTO: CATHERINE THOMAS, TAIPEI TIMES

Today we are going to make a bouncy ball. This experiment is best done by the sink.

What you will need:

Childsafe glue (PVAc)

Borax (be careful, borax is toxic and should not be eaten)

Cornstarch

A tap

Food coloring

A disposable chopstick (for stirring)

A cut-off plastic bottle or disposable plastic cup

A disposable soup spoon (for measuring - holds 20ml)

A cup (for holding the cornstarch)

▲ Put a spoonful of cornstarch into a cup.

▲ Put a spoonful of glue into the bottle. Wash the spoon with warm water. Dry the spoon.

▲ Add a drop of food coloring to the glue. Mix in well.

▲ Measure out an eighth of a spoonful of borax.

Carefully sprinkle the borax evenly over the surface of the glue. Don't stir it!

▲ Add the cornstarch on top of the glue and borax. Do not stir it.

▲ Count to 15.

▲ Using the chopstick, stir the mixture until it is all clinging to the chopstick.

▲ Remove the mixture from the bottle. Place it between your palms. Turn on the cold water tap and roll the mixture into a ball shape underneath the running tap.

▲ When the ball feels firm you can turn off the water. Wait a couple of minutes for the ball to dry out and then try bouncing it! Be careful where you leave your ball - others might mistake it for food. It musn't be eaten! If you want to keep your ball, store it in a ziplock bag.(CATHERINE THOMAS, STAFF WRITER)